A conventional key fob is a decorative item attached to a keychain. Because the form of many electronic keys often resembles that of conventional key fobs, such electronic keys have come to be referred to as electronic key fobs. As electronic key fobs have become increasingly common, they are often more simply known as fobs. Fobs are typically used to control access to rooms or the operation of vehicles. Fobs usually operate using infrared line-of-sight technology or radio-frequency identification (RFID) technology. Where RFID technology is used, the fob includes a passive RFID tag. A passive RFID tag includes circuitry and an antenna designed to receive a signal from an RFID interrogator and to transmit a response to the RFID interrogator. A passive RFID tag does not have a power source, but rather uses some of the energy received in the signal from the RFID interrogator to provide power to the circuitry of the passive RFID tag to transmit the response.